How to select only required variables/columns in SAS and R tidyverse?

This post is part of 'SASnR | Subset variables (columns)' series

When working with data, we frequently need to work with only a selected set of variables. For this, we need programming features to subset only required variables or columns.

There are multiple ways of selecting only required in both SAS and R tidyverse. Below is one basic approach in both SAS and R.

Let us assume that we have a dataset named "class" with 5 variables named Name, Sex, Age, Height, Weight.

Name	Sex	Age	Height	Weight
Alfred	M	14	69	112.5
Alice	F	13	56.5	84
Barbara	F	13	65.3	98
Carol	F	14	62.8	102.5
Henry	M	14	63.5	102.5
James	M	12	57.3	83

Let us assume that we only need Name, Sex and Age variables.

Name	Sex	Age	Height	Weight
Alfred	M	14	69	112.5
Alice	F	13	56.5	84
Barbara	F	13	65.3	98
Carol	F	14	62.8	102.5
Henry	M	14	63.5	102.5
James	M	12	57.3	83

We can create a new subset dataset (tibble/dataframe) using the below code.

SAS code

data class;
   set sashelp.class;
   keep namge sex age;
run;

Notes:

data statement is used to specify the name of the newly created dataset
set statement is used to specify the name of the input dataset
keep statement is used to specify the names of the required variables
note that sas is not case sensitive in terms of variable/column names

R tidyverse code

library(tidyverse)
library(haven)
class<-haven::read_sas("class.sas7bdat")
class_selvars<-select(class,Name,Sex,Age)

Notes:

tidyverse is loaded into R session using library function
As haven is not a core tidyverse package, it has be explicitly loaded
read_sas function of haven is used to read the sas dataset into R session as a tibble
select verb of dplyr of tidyverse is used to select only required columns
the first argument of select verb (function) is the name of the input tibble, followed by the list of required variables each separated by a comma
note that R is case sensitive in terms of variable/column names - so we need use the same text case

Example class dataset (sas dataset) can be downloaded from here.

Post categories
SASnR
SDTM

How to select only required variables/columns in SAS and R tidyverse?

SAS code

Notes:

R tidyverse code

Notes:

List of other posts

SDTM

General

SASnR

Introduction

Reading data

Creating sample data

Subset variables (columns)

Subset observations (rows)

Sort (order) observations

Transpose/Restructure data

Obtain frequencies

Descriptive statistics